Multipart core



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Patented, dan, i, 392% y narran stares restera earners essaies@ ALLEN IB. NORTON, 0F CLEVELAND, OHIO, ASSIGNOR T0 ALUMINUM COMPANY OF AMERICA, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANA.

I MULTIPAET CORE.

Application led February 23, 1924. Serial No. 694,480.

This invention relates to moldsfor cupshaped articles and particularly to a sectional core for a piston mold.

. One object ofthe invention is to construct a core composed of aplurality of rugged interlocking sections for a piston having an inwardly extending projection on its end wall.

Another object is to construct a sectional core comprising a center section and side sections, the sections being aligned by longitudinal enlargements 'on the center section and corresponding recesses in the side sections cooperating therewith.

Another object is to construct a core cornposed of three sections of relatively the same cross sectional dimensions and weight for a cup-shaped casting having inwardly extending projections on the end and opposite side walls.

A further Objectis to construct a durable, rugged three part permanent core, for a piston having a boss on the inner side of the end wall and oppositely dis osed wrist pin bosses carried by chordal we s.

Other objects will appear and be pointed out hereinafter.

In the drawings attached hereto and forming a part of this application:

Figure l is a fragmentary cross sectional view of a piston mold provided with my improved form of core.

Figure 2 is a side elevation of my improved form of core. e

Figure 3 is a fragmentary cross sectional view similar to Fig. l, but showing the core partly removed from the mold and casting.

Figure 4l is an inner end View of an assembled core embodying my invention, and

Figure 5 is a perspective view pf a piston cast in a mold employing my core. y

Although my invention relates generally to cup-shaped articles, it will be described hereinafter in connection with a piston mold of the type disclosed in the patent to Joseph H. Bamberg issued March 4th, 1919, Serial No. 1,296,588. Inasmuch as the present invention relates primarily to the construction of a core, only enough of the mold structure at present in extensive use and disclosed 1n the aforementioned Bamberg patent is shown herein to indicate to those skilled in the art yon the casting 3. The end wall of the castn ing cavity is formed by the mold base l. rlhe Y mold halves 2 near their upper sides may carry bushings 6 to form at their lower ends a :part or all of the end wall of thel piston skirt, the inner surfaces of the bushings serving to hold the core sections in assembled relation when the mold halves are secured together. To facilitate ready escape of air and gases from the casting cavity as the metal is being fed into the casting cavity, numerous small air vents 7 are provided between the mold halves 2 and bushings 6, as well as bev tween the bushings 6- and the adjacent core sections, the former recesses being shown greatly exaggerated and the latter recesses being not shown.

The piston casting 3 is provided with `oppositely disposed wrist pin bosses 5 preferably cast hollow and in this instance carried by cross webs 8 which extend in substantially parallel relation across the piston at substantially right angles to a line joining the bosses. A rib 9 is provided across and integral with the head of the piston and extending downwardly therefrom to and being united integrally with the bosses. At approximately the center of the inner end wall of the piston, a centering boss l0 is provided for use in machining the piston. sume various sizes and shapes, but as shown herein, it is substantially circular and of slightly greater cross sectional dimensions than the width of the rib 9 which adjoins. It will be noted that the wrist pin bosses 5, the rib 9 and the centering boss 10 are arranged in a plane substantially diametrically of the piston.

The core embodying my invention and adapted to the casting of a piston, such as is This boss l0 may asinwardly along figuration is shown in this figure,

enlargements on certain of the sections and recesses co-operating therewith on other sections. In the present embodiment of my invention, the core comprises a center or middle section 1 1 and two oppositelyl disposed side sections 12.. The center sectioii-11 has on its opposite sides longitudinally extending raised portions or enlargements 13 and a centering boss recess 14 on its bottom. The ends of the center section are curved and form, with the outer sides of the side sections, the inner side walls of the piston. Each side section 12 is provided on its inner surface with a longi-` tudinally extending recess 15 adapted to cooperatel with the raised portion or enlargement 13 on the center section to align the 'side section therewith, and also contains on its outer surface-an inwardly extending recess 16 in which the boss 5 and the boss carrying wall 8 may be cast. The assembled sections 11 and 12 have a rib recess 17 formed in the bottom thereof to form the rib 9A on the casting.

By referring to Fig. 4 it will be noted that the center section 11 is provided with aiongitudinally extending raised portion or enlargement-13 .which is greater in width than the cross sectional dimensions of the centering boss recess 17. Although these portions- 13 may be variously shaped, a desirable con- -where the outer surface at right angles to the web recess 17 is substantially at right angles to this recess. With ing recesses of the shape and size just described, it will be evident to those skilled in the art tliatthe side sections 12 can be moved the rib 9 until therecess 15 is above the centering boss 10 without, however, bringing sharp surfaces into contact with the st-ill highly heated rib 9 and causing -possibleinjury thereto.

The method of removing a core embodying my invention from a piston casting 5 Ais indicated in Fig. 3 of the drawings, where a center section 11 has beenwithdrawn longitudinally from the casting and between side sections 12, after which one side section 12 is moved inwardly until it clears the boss 5 and the boss carrying w'all 8, after which it may be removed longitudinally from the casting. A similar procedure will remove the other section 12.

It will be noted that I have provided a sectional core for a pistonhaving inwardly pro- 'jecting bosses which is composed of a plurality of sections ofA substantially the saine weight and thickness, while at the saine time providing sections which are exceptionally rugged and capable of withstanding the hard usage to which such mold parts are subjected walls 8 project inwardly of the raised portions andk co-operat-` in ordinary use. Although the boss Vcarrying piston to a considerable extent, I have been able to provide side sections 12 which have the requisite strength to resist the ordinary wear and tear and tendency to warp age due to the temperature of the metal being cast, and at the same time have provided means for aligning the several sections when in assembled position. The aligning means, including the raised por- Vtions 13 and the (zo-.operating recesses 15, alsoposses's the further function of making possible the formation of a centering boss on the in-l ner side of the end wall of the casting. It will be understood, of course,' that the centering boss 10 may be cast either with or independently of the rib 9. 'y

Having thus'described my invention so that those skilled in the art may what I desire to secure lbyl etters Patent is ractice the same,

defined in what is claimed. It is to be under-jl stood, however, that various changes and alterations not amounting to invention may bev made in the embodiment of my invention herein disclosed, Awithout departing from the spirit and scope of my invention.

What is claimed is:r

1. .A sectional core, for a piston having an inwardly projecting centeringv boss on the end wall, which comprises 'a middle-section having a centering boss recess in its end surface and raised portions on the sides thereof, thev raised 'portions and centering boss being aligned diametrically of the core the said .raised portions being larger than the boss rechess and extending lengthwise of the said section, andside` sections having interlocking engagement with the middle ,section and eachhaving a wrist pinrecess in its outer surface. 2. A sectional core, for a istonl having an inwardlyprojecting centering boss on theV end wall, which comprisesa middle section and two side sections co-op'erating therewith,.-

the said side sections. each having a wrist pin boss recess in the outer surface and a recess lengthwise of the inner surface, the said central section having raised portions lengthwise of oppositesides co-operating withtIie .said

recesses on the inner surfaces of the side sections, and acentering boss recess on the inner end, the said middle section, the wrist'pin boss recesses, he cio-operating raised portions, re-

-cesses and centering boss recess being aligned diainetrically of the piston.

3. A newL and improved three part core, for a piston having an interior centering boss on the end wall, which comprises amiddle section having a centering boss recess in the end surface and raised portions 'aligned withthe said recess extending lengthwise of the op osite sides, .and side sections each provided with'recesses on 'its inner surface corresponding to the raised' portions and wrist pin boss recesses on its outer surface.

j 4. A new and improved core, foral piston having an interior centering boss on the end tions of greater diameterthan the centering wall, which comprises three sections separated on lines substant-ially at right angles to a line joining the wrist pin bosses, the middle section having a centering boss recess in the end vsurface and raised portions extending lengthwise of the side surfaces, the side sections having wrist pin boss recesses and receses co-operating with t-he raised portion, all the said recesses and raised portions being diametrically aligned with a. line joining the boss recesses.

5. A new and improved piston core, having diametrically aligned wrist pin bosses and a centering boss recess in the inner end thereof, the said core being split longitudinally into three parts on planes substantially at right angles to the diametrical line joining vthe said wrist pin bossl recesses, the said planes being irregular adjacent the said diametrical line and penetrating into the side sections an amount substantially greater than the diainetrical dimensions of the said centering boss recess. j

6. A core, for a. piston, composed of three sections of roughly the same thicknesses, the middle section having a centering boss re- K cess in its inner end, each side section having in its inner side a lengthwise groove of greater cross sectional size than the said boss recess, and raised portions on the sides of the `middle section interlocking with the grooves in the side sections.

7. A core, for a piston, comprising three sections of roughly the same size, the middle section having a. centering boss recess in its inner end, the said sections having interlocking tongues and grooves aligned with the boss recess and of greater cross sectional area than half the corresponding area of the boss recess.

8. A sectional core having an end and sides adjacent thereto shaped to form the interior of a hollow object comprising a c'enter sectionI having longitudinally extending enlargements at an intermediate portion of its sides and a plurality of side sections having longitudinally extending recesses cooperating with said enlargements.'

9. A threepart core for forming the interior surfaces of a hollow object about its end portion comprising a center section having longitudinally extending enlargements at an intermediate portion ofthesidescontacting the outer sections, the said outer sections having longitudinally ext-ending recesses conformingto said projections.

10. A core, for a piston having oppositely located wrist pin bosses, a rib extending across the inner side of the end wall of the piston in diametrical alignment with the said bosses and a centering boss coinciding with and of greater diametrical and longitudinal dimensions than the said rib, which comprises a middle section having a centering boss recess in its inner' end, and longitudinal raised porboss recess along its opposite sides, and two side sections having their inner sides formed to cooperate with the said middle section, and their outer sides formed with wrist pin boss recesses, the inner end of the assembled sections bein tending ri recess.

11. A core, for a piston, composed of a middle and two side sections, each side section being formed with a wrist pin boss recess in its outer surface and? the-assembled sections being formed with a continuous rib recess extending across the inner end in diametrical alignment with the said boss recesses, the middle section also being formed with a centering boss recess coinciding with but of greater depth-than the rib recess, the co-operating side surfaces of the middlesection and side sections being formed with interlocking raised portions and recesses lrespectively, of greater dimensions than the said centering boss recess.

12. A core, fora piston, composed of a middle and two side sections, each side section being formed with a wrist pin boss recess in its outer surface and the assembled sections `being formed with a continuous rib recess extending across the inner end in diametrical alignment with the said boss recesses, the middle section also being formed withy a centering boss recess coinciding with but of greater ldepth than the rib recess, the co-operating side surfaces of the middle section vand side sections being formed with longitudinally extending interlocking raised portions and recesses respectively of greater formed with a diametrically exdimensions than the said centering boss recess.

13. A core, for a piston, composed of a. middle and two side sections, each side section being formed with a wrist pin boss recess in its outer surface and the assembled sections being formed with a continuous rib recesserating side surfaces of the middle section and sidesections being formed with vinterlocking raised portions and recesses trapezoida-l 1n cross section respectively with one surface of the trapezoid extending at substantially right angles tothe said rib recess the dimensions 'of the said portions being greater than those of the said centering boss recess.

14. A three partv core the end portion of which is adapted to form the interior surfaces of a hollow object cast thereabout comprising a center section and two side sections adjacent thereto, Ithe center section being wider at its center than at its ends.

15. A three part core the end portion of which is adapted to form the interior surfaces v of e hollow object cast thereabout comprising of 'a hollow object cast thereabout comprising a center section and two side sections cona cruciform center section and two side sec' 10 forming to the sides thereof, the sides of the .tions having longitudinally extending recenter section being provided with long'icesses to receivethe transverse arms of the 5 tu'dinally extending ribs vintermediate the cross.

ends of the section. v In testimony'whereof I hereunto ailx my 16. A three part core the end portion of signature this'lSth day of Februar, 1924. which is adapted'to form -the interior surfaces y ALLEN B. NO l TON. 

